class MyValue{
    public int val;
}
public class Test {
    public static void swap(MyValue myValue1,MyValue myValue2){
        int tmp=myValue1.val;
        myValue1.val=myValue2.val;
        myValue2.val=tmp;

    }
    public static void main(String[] args) {
        MyValue myValue1=new MyValue();
        myValue1.val=10;
        MyValue myValue2=new MyValue();
        myValue2.val=20;
        System.out.println(myValue1.val);
        System.out.println(myValue2.val);
        System.out.println("==========");
        swap(myValue1,myValue2);
        System.out.println(myValue1.val);
        System.out.println(myValue2.val);
    }
}
